Linux Mint 13 (and subsequent releases 14, 15, 16, and 17) introduced some changes regarding local language support and how it's setup. As a result, you will see the following warning, for example when running update-initramfs:

Warning: No support for locale: en_US.utf8

This is because locale-gen is using an archive file to store all the locales, but many utilities are still looking for the locale files.

Have a look at /usr/lib/locale/. If your output looks like this, read on:

You're welcome! Though I believe it's only a cosmetic issue. Can't remember that it caused any problems. In case it gets fixed, you could run sudo locale-gen --purge to get back to the archive way of storing locales (haven't tried it though).

ddalley wrote:So, a year later, what are the chances of this finally getting fixed?

I presume that only one utility needs to be updated, to use the more modern method of looking for locales.

Just for reference, I'm NOT following my own instructions, that is I use the new locales format (archive file) for over a year now and I never had any issue with it. With certain updates it throws error messages at me, but that is all - no problems whatsoever. Perhaps this is the reason no one bothers with it: if it ain't broke, don't fix it!

Thanks! I'd seen this error when installing things via apt all the time, however because I'm on en_GB I'd always assumed it was because whatever software I'd installed only had translations for en_US and not the GB version.